Improvement in bleaching paper-stock



UNITED vSTATES PATENT OFFICE.

JOEL 'IIEFANY, OF ALBANY, AND HARRISON B. MEEOH, OF FORT EDWARD,

' NEW YORK..

IMPROVEMENT IN BLEACHING PAPER-STOCK.

Specification forming part of Letters Patent No. 56,833, dated July 31, 1866.

To all whom it may cohcem:

Be it known that we, JOEL TIFFANY, of

the city of Albany and State of New York,

7 cess of Bleaching Paper-Stock for the Manufacture of White Paper; and we do hereby declare the following to be a full and exact description of the same. A

Our improved process consists in taking paper-stock, after it has been boiled in a caustic alkaline solution, and has been washed and made ready for the process of bleaching by the methods well known to manufacturers of paper from straw and other fibrous substances, and saturating the same thoroughly with a solution of chlorine. We place the same in a close vessel. We then close the Vessel airtight, and force into the same a diluted chlorine gas, which may or may not be mixed with atmospheric air, as is most convenient, until an internal pressure of thirtypounds to the square inch, or upward, is obtained. The object of the pressure is to bring the chlorine in contact with every part of the stock, so that the process of bleaching may be completed within one-half of the time ordinarily required for that purpose. The chlorine gas is forced into the close vessel by means of a force-pumpa means Well known to the public.

We do not claim the bleaching of paperstock by the use of chlorine gas or the bleach ing, of such stock under pressure merely; but

What we do claim, and seek to secure by Letters Patent, is-

The process of bleaching paper-stock under pressure produced by forcing a weak chlorine gas, withor without atmospheric air, into a close vessel contain the stock, in combination with the. use t solution of chlorine, with which the stock to be bleached is saturated, substantially in the manner and for the purposes herein described.

JOEL TIFFANY. H. B. MEEGH.

Witnesses:

J 0s. F. WINNE, EDWARD WADE. 

